Filter structure for vacuum cleaners



Sept. 26, 1939. Q A BRQCK 2,173,960

FILTER STRUCTURE FOR VACUUM CLEANERS Original Filed Dec. 18, 1935 2Sheets-Sheet l 11v VENTOR 622 222722? 17, Eroci Ame. A TTORNEYS.

Sept. 26, 1939. Q A BRQCK 2,173,960

FILTER STRUCTURE FOR VACUUM CLEANERS Original Filed Dec. 18, 1935 2Sheets-Sheet 2 f f I I 5 I ATTORNEYS.

Patented Sept. 26, 1939 FILTER STRUCTURE FOR VACUUM CLEANERS Clarence A.Brock, Detroit, Mich., assignor to Rexair, Inc., Detroit, Mich, acorporation of Delaware Original application December 18, 1935, SerialNo.

Divided and this application July 6,

1937, Serial No. 152,071

1 Claim.

This application is a division of applicants prior co-pendingapplication Serial No. 54,966, which has now become Patent No.2,158,717, May 16, 1939.

The invention set forth herein relates generally to vacuum cleaners andmore particularly to a novel and improved form of vacuum cleanerconstruction embodying in a single unitary casing a mechanical dustseparating unit and a filter for finally purifying air which hasinitially been purified by the mechanical dust separating means. Thepresent invention contemplates the provision of a compartment within themain casing for housing said filter and in addition, contemplates theprovision of a relatively easily accessible means whereby the filter maybe bodily removed from the filter compartment in the event it isnecessary to empty or clean the samg.

The wall of the filter compartment is provided with a series of louversor openings which serve to permit air passing through the filter bag toescape from the casing. In the event it'is desired to utilize theapparatus of the present invention as a blower such as is oftendesirable in cleaning operations, means are provided to achieve thisend. An aperture is provided for connecting a flexible conduit to thefilter compartment in order that air discharged from the filtercompartment will be discharged into the conduit.

The present invention contemplates the provision of means associatedwith the apparatus for connecting the flexible conduit which meansincludes a closure adapted to block the louvers or apertures in the wallof the casing thus insuring that all air delivered to the filtercompartment will be discharged through the blower conduit.

Many other and further objects, advantages, and features of the presentinvention will become clearly apparent from the folowing specificationwhen considered in connection with the accompanying drawings forming apart thereof.

In the drawings:

Figure 1 is a side elevational view of a dust separator elementembodying the improvements of the present invention.

Fig. 2 is a vertical sectional view substantially enlarged takenlongitudinally through the dust separator construction disclosed in Fig.1.

Fig. 3 is a fragmentary sectional view taken substantially on the line3-3 of Fig. 2 illustrating in detail the means for closing the filtercompartment.

Fig. 4 is a fragmentary sectional view taken through the filtercompartment illustrating in de- V .series of screws 21.

(c1. nae-51) tail the interior construction and configuration of thefilter compartment and disclosing a blower conduit secured incooperative relation thereto.

Fig. 5 is a fragmentary transverse sectional view taken substantially onthe line 5--5 of Fig. 2 ilustrating in detail the manner in which thefilter bag is disposed within the'filter compartment.

With more particular reference to the drawings, the specific embodimentof the invention shown therein comprisesin' general a casing l0 whichmay be formed of composite sheet metal or other suitable constructionand which is illustrated as a casting. The casing is preferaby generallyoval in shape and is provided in its central portion with a verticallyextending partition wall II. The casing as a whole is open at the topand is adapted to receive a suitable cover l2. This cover I2 is providedwith a flange l3 at its marginal edge adapted to mate with acorresponding flange I4 on the upper marginal edge of the casing l0.

On one side of the partition wall I l in the casing l0 is'mounted ablower housing l6 which. has mounted therein a suitable electric motorI! serving to drive a plurality of centrifugal fans l8 which provide amultiple stage blower construction tending to draw air axially downwardthrough the blower housing IS. The blower housing is provided at itsupper end with an annular flange I9 which has a. groove in the axialface thereof. A cover plate 20 has a grooved face adapted to mate withthe grooved flange l0 and is secured thereto by means of a suitableannular A pair of partitioning members 23 and 24 have registeringcircular apertures therein slightly larger than the diameter of theflange l9 and associated cover plate 20, and have complemental circulargrooves in their adjacent faces. An annular packing strip 25, havingbeaded edges, and preferably formed of rubber or suitv able resilientcomposition, has one beaded edge clamped between thecover plate 20 andflange 19 by means of the screws 2| and has its other beaded edgeclamped between the partitioning members 23 and 24 and securely lockedin place by means of bolts 26. It will be appreciated that the bolts 26not only serve to lock the partitioning members 23 and 24 inpredetermined position but also serve to interlock the flange M on thecasing II) to the flange l3 on the cover l2, thus securing the coverfinish moldings I] to provide an attractive exterior appearance.

The cover plate 20 has mounted substantially centrally thereof anannular series of ball bearings 30 in which is journaled a blower shaftII. This blower shaft Si is preferably directlyconnected to the electricmotor I! and serves to drive the vertical series of centrifugal fans 18which tend to draw air downwardly through the blower housing.Surrounding the bearing structure ll.

in the cover member 20 is an annular series of inlet apertures 32 whichserve to permit the fiow of air from the upper portion of the casingenclosed by the cover plate, downwardly into the multi- .rate peripheralsurface of substantial area exists internally of the dust separatorelement because it has been found that if dust passes through theslots'in the surface of the element, it tends to build up on suchsurfaces and hence necessitates relatively frequent removal of the dustseparator element and cleaning of the interior thereof.

The specific shape of the separator element 05 has been found to be avery important factor in preventing the accumulation of dust interiorlythereof. It has been found that by accurately regulating the shapeproportions of the separator elements building up of dust on the insidesurface is eflectively prevented. It has been found particularlysatisfactory to form the. dust separator element of a relatively shortaxial length so that its axial length is approximately onethird of thediameter of its large end and about one-half the diameter of its smallerend. The actual physical size of the element as a whole is relativelyunimportant as long as the proper proportions are maintained. It hasbeenfurther found particularly desirable that the separator be formed with aflat top which lies in a plane transverse to the axis of rotation of theelement as a whole.

The dust separator element ilis provided at its lower axial end with aradially extending flange- 36 which is mounted on a suitable spider llsecured to the shaft of the motor ll. It will be seen that as the motorI! is run, air will be drawn inwardly through the slots in the separatorelement 35 by means of the centrifugal blowers. l8 and dust in such airwill impinge upon the rounded surfaces of the bars servingto definethese slotsand be centrifugally driven away. In order to insure that nodust-ladenair will enter the necessary clearance between the dustseparator element and the cover plate It, a series of radially disposedvanes 31 are formed on the lower side of the spider 38. These vanes orblades act as a centrifugal fan and maintain a constant but relativelysmall outflow of air through this space, thus insuring that nodust-laden air' will enter.

' the interior of the dust separator element at this ammo and that amuch smaller, but equally constant outflow of air will be created by thevanes 3'! cperatingin the clearance between the dust separatorelementand the cover plate 20, thus insuring that all air passing through theannular series of inlet ports 32 to the blowers will be substantiallydust-free.

The casing It has an inlet opening 40 which may be formed integrallytherewith and may be internally threaded to facilitate the connection.'of a flexible conduit ll thereto which is adapted to be connected toany suitable nomle, such for example as 42, Aninlet duct 45 is connectedto the inlet opening 40 and serves to provide communication between theinlet opening 40 and the space within the casing adjacent the dustseparator element 35 above the partitioning mambers, I! and 24. Thisconduit preferably extends arcuately around the electric motor I I inthe base of the casing and thence upwardly. through suitable registeringapertures in the partitioning members 23 and 24. J

In the lower side of the casing on the opposi side of the partition wallfrom the portion in which the motor and blower are mounted; is a filtercompartment generally designated as 0. Suitable louvers ii are providedin the wall of the casing to permit the .escape of air from the filtercompartment 50. An outlet aperture is formed in the partition wall II toprovide communication between the compartment housing, the motor andblower, and the filter compartment and this aperture has preferablypermanently mounted therein a nipple which is adapted to receive a dustfilter bag 56 of a shape conforming substantially to the shape of filtercompartment 0. This filter bag 56 is preferably secured on the nipple 55by means of a garter spring 51 Ind or other suitable securing means. Thefilter compartment is closed at its upper side by' means of a removablepartition member 60 seated on a suitable gasket SI and having one of itsedges secured in a recess 62 formed in the casing ll. The opposite edgeof this partition member I. is retained in position by means of a springelement 63 secured to the partition wall I I by means of a pair of bolts64. This spring element 63 has a further important function which willhereinafter be clearly seen.

From the foregoing, it will be clear that dustladen air taken in by thenozzle 42 will be conducted through the flexible tube ll into the inlet40. From the inlet 40 it will be conducted upwardly through thepartition walls 23 and 2| into the upper portion of the casing in whichis located the rotary dust separator element 35.

It will be clear that the suction pressure generated by the multi-stagefan It driven by the electric motor I! will draw this dust-laden airtoward the separator element 35 and that the separator element willfunction to remove from the air by centrifugal force, the dustparticles, and will draw only substantially pure processed airdownwardly through the blower housing. It will be seen that the onlyoutlet for the air drawn into the blower housing is through the nippleII in the partition wall H and hence into the filter bag It securedthereto. The filter bag will, therefore, serve to collect any dust whichwas not extracted from the air by means of the centrifugal dustseparator element 35 and consequently only substantially dust free airwill be passed from the filter compartment 50 out through the louversII.

It will likewise be seen that due to the action of the blowers It, asubstantial pressure differential will be created between thecompartment above the partitioning members 23.and 24. and thecompartment in which the blower housing is mounted. Due to thissubstantial pressure differential the greater pressure in the lowercompartment in which the blower housing is mounted, will tend to movethe blower housing, blower and motor connected thereto, upwardly towardthe area of decreased pressure. This upward movement of the blowerhousing and motor will be resisted by the resilient packing ring element25 which is clamped between the partitioning elements 23 and 24 at itsouter periphery and between the blower housing l6 and cover plate 20 inits inner periphery. This pressure differential has been found to besufficiently great so that the entire blower housing, dust separator,blower and motor associated therewith, will be raised slightly when theblower is operated, thus tensioning the res lient packing element 25 andsupporting the blower housing entirely free from the casing structureexcept for the interconnection of the resilient packing member 25. Itwill be appreciated that this construction serves materially to preventthe sound and vibration resulting from the relatively high speedoperation of the blower and dust separator elements from beingtransmitted to the casing and consequently virtually eliminates thenoise usually attendant upon the operation of machines of this generaltype. A resilient padding element 66 may be securedto the lower axialend of the motor in order to cushion this portion of the apparatus withrespect to the casing II]. It will be appreciated, however, that as theblower is operated, the motor, blower housing, and dust separator, whichtogether provide a substantially unit construction, will, due to theaction of the blower, be raised from the floor of the casing l0 and willbe maintained entirely out of contact therewith during the time themachine is operated. The function of the resilient cushioning member 66is merely to provide a resilient seat for the blower housing duringtimes when the machine is not in operation. Consequently, it will beseen that this resilient cushioning member serves to relieve the annularresilient member 25 from unnecessary strain in supporting the blowerhousing when the machine is not operating. It is to be particularlynoted that the rubber ring 25 is placed under tension as the blower unitrises in operation. This is important from the standpoint of reducingthe transmission of audible vibrations from the blower unit to the maincasing as it has been found that were such rubber placed undercompression, instead of tension, the reduction of noise would be ratherinsignifieant as compared to the present case where the rubber is placedunder tension.

A suitable circular aperture 10 is provided in the upper surface of thecover I2 and has surrounding it a packing member ll upon which is seateda removably mounted glass cover panel 12 retained in position by meansof a suitable frame I3. It will be clear that this cover panel 12 issufliciently large in order that access may be had to the rotatable dustseparator element 35 and that this element may be cleaned, adjusted,dismounted or replaced at will without disturbing the mounting of thecover l2 on the casing l8.

As may be desired, a handle 14 may be suitably secured to the top of thecover member l2 in order to provide convenient means for transportingthe dust separating apparatus from place to place. The opposite end ofthe cover section l2 to that in which the rotary dust separator eletheswitch 19 and connector block 11 down to the electric motor II.

In the space between this portion of the cover section l2, justdescribed, and the upper surface of the filter compartment 58, islocated a removable slidably mounted dust bin 85. This dust binpreferably has an exterior face provided with a suitable handle 86 andmates closely with the adjacent walls of the casing i8 and cover l2. Theupper marginal edge of the dust bin is preferably headed and providedwith a finish molding 88 which, when. the dust bin is slid intoposition, will mate with the finish molding 28 on the lower partitionmember 24 to provide a substantial continuation thereof which it will beseenextends entirely around the dust separator casing. The drawer ordust bin 85 preferably extends substantially the full width of thecasing l8 and the under side of the partition member 23 is preferablyprovided with a resilient sealing strip 90 seated therein throughout theextent which this partition element mates with the drawer in order toprovide an effective and tight seal of the partition member 23 withrespect to the top marginal edge of the bin 85. The rear wallof the binon its exterior side substantially in the central portion thereof isprovided with a spearhead 9| preferably formed integrally with thedrawer and adapted to enter between the spaced prongs 92 of the springelement"63. These prongs 92 are preferably formed by bending suitablelateral projections on the spring element 63 between the points at whichthis spring element is secured to the partition wall II. It will thus beappreciated that the dust bin 85 is maintained in predetermined positionwith respect to the casing in which it is mounted and that it is lockedin position by means of the spring element 92 and the mating spearhead9|. It will further be seen that the top marginal edge of this drawer iseffectively sealed by means of the resilient sealing element 90.

A suitable aperture 95 interconnects the portion of the casing in whichthe bin 85 is mounted with the portion of the casing surrounding therotary separator element 35. Due to the centrifugal action of the rotaryseparator element 35 the dust particles in the air entering the portionof the casing in which this element is located will be driven to thatportion farthest away from the rotary separator element 35 and willconsequently drop directly into the dust bin 85. From the foregoing, itwill be appreciated that as the nozzle 42 serves to draw dust fromarticles being cleaned, this dust will be conveyed through the inlet 40and intake conduit 45 into the chamber surrounding the rotary dustseparator element. At this point the dust particles will, by means ofthe rotary dust separator, be separated from the air and will drop intothe bin 85. The clean air passes downwardly through the multiple stageblower and out through the filter bag 56 which serves to subject the airto further cleaning action. From the construction described above, itwill be apparent that the dust bin ll may be conveniently removedwhenever it is desired by bodily separating it from the casing ll.Accumulated dust, therefore, may be emptied from the bin II atconvenient intervals without in any way disassembling the machine.

At certain times it is found desirable to use a machine of this generaltype for providing a blast of air for various cleaning operations andother purposes. In order to conveniently effect this resuit, the filtercompartment is provided with an aperture III internally threaded insubstantially the same size and manner as the inlet aperture 4|. Innormal operation of the machine, this aperture I may be left open as maybe desired and some of the exhausted air from the dust separator will bedischarged therethrough. How ever, the greater portion of the exhaustedair will pass outwardly through the louvers Ii. While any suitable meansmay be used to close the louvers II when it is desired to use theapparatus as a blower, it is preferably to provide a convenient meansfor positively and efi'ectively sealing these louvers during such time.One way in which this may be efi'ectively accomplished is by means of asheet metal element llll bent to a configuration substantially the sameas the exterior of the casing and provided throughout a substantial areain its end portion with a sealing strip of soft rubber or otherresilient material I02: which when the strip III is mounted in position,serves to cover and seal the louvers 5|. This element lti may beretained in place by means of a fitting or collar I" which is screwedinto the threaded aperture Ill. The collar Ill may be internallythreaded and is adapted to receive a complementally formed portion Isecured to the end exhausted from the filter compartment will be' forcedout through the aperture I03 and may be directed as desired by anysuitable apparatus con ventional in the art.

Many other and further modifications of the invention falling within thescope of the subjoined claim will be apparent to those skilled in theart.

What is claimed is:

In a vacuum cleaner construction, a casing, said casing being preformedinternally to provide a filter compartment, said casing having aplurality of louvers in the outer wall thereof serving to permit theescapeof air from said filter compartment, said casing having inaddition an aperture serving to permit the connection of a blower tubehaving communication with said compartment, and means for sealing saidlovers to compel the air passing outwardly from said compartment to passthrough said blower tube, said last named means including a resilientmember engaging the edges of said louvers and a sheet metal backingmember.

CLARENCE A. BROCK.

